(under subclass 74) Subject matter wherein the output coupling network is of the passive type and is so designed as to pass waves of a desired frequency or band of frequencies with little attenuation while highly attenuating waves of other or undesired frequency or band of frequencies.
SEE OR SEARCH THIS CLASS, SUBCLASS:
32+, for oscillators having automatic frequency stabilization utilizing a stable heterodyne oscillator and wherein the frequency discriminator may be of the passive-filter type.
43, for beat frequency oscillators having a filter in the mixer output.
SEE OR SEARCH CLASS
333, Wave Transmission Lines and Networks, 167+, for passive type wave filters, per se.
